1. Field of the Invention
The present invention relates to power tools and, more particularly, to a belt tension adjuster.
2. Prior Art
U.S. Pat. No. 3,866,320 to Progl discloses a guide bar adjustment for a chain saw with an adjusting screw, an adjusting member, two gears connecting them, and a threaded follower nut that rides on the adjuster screw when it is turned to move the guide bar. U.S. Pat. No. 4,620,367 to Tubesing discloses a saw drive tensioner with a bolt for simultaneously adjusting tension in two belts. U.S. Pat. No. 4,583,961 to Kawasawa et al. discloses a belt tensioner with an adjustable bolt, a spring, and a slider. U.S. Pat. No. 3,194,284 to Walker discloses a tension adjuster for a chain saw. The adjuster has a screw, a spring, a lug and a nut. The lug projects into an aperture in the blade. U.S. Pat. No. 2,970,587 to Estes discloses an adjusting mechanism with a stud member and an adjusting screw. U.S. Pat. No. 4,618,336 to Isobe discloses a belt stretching mechanism with a bolt, a slider, a spring and a hook. U.S. Pat. No. 4,708,695 Sugiyama discloses a member with teeth that is biased by a spring and has a bolt to lock with a hole. The Partner K650 Mark II saw, sold by Partner Industrial Products, has a belt tensioner where a spring determines tension after two nuts have been loosened and a screw is adjusted to a reference mark.
Various problems exist with prior art power tools. One problem is that screws, such as that in the Partner K650 Mark II saw, are located in an awkward orientation in order to be conveniently used. Another problem is that single standard screws are relatively slow to longitudinally move due to limited screw pitch.
It is an objective of the present invention to provide a new and improved power tool belt tension system.